Floatless carburetor



E. E. HALIK FLOATLESS CARBURETOR Feb. 26, 1957 Filed March 8, 1954 QEQT57. 60

INVENTOR EUGENE E. HALIK ATTORNEYS E. E. HALIK Feb. 26, 1957 FLOATLESSCARBURETOR 2 Sheets-Sheet 2 Filed March 8,1954

.m L MA T H ms m ms G U E. O 5 LS a Y 4 7 B 3 8 5 ATTORNEYS UnitedStates Patent 2,783,033 FLoATLEss CARBURETOR Eugene E. Halilr, KewGardens, N. Y. Application March 8, 1954, Serial No. 414,537 10 claims.Cl. 2131-36 This invention relates to a float-less carburetor forinternal combustion engines, more especially a carburetor for use invehicles. 7

Float-less carburetors, as heretofore made, have been characterized bythe use of diaphragms responsive to small pressure differentials, and byneedle valves requiring weak springs which fatigue easily. Incarburetors of this type, the presence of fine dirt particles in thepassages and jets tends to impair usefulness; proportioning of fuelsupply to engine-suction alone tends to cause oversupply of fuel at fullthrottle, and proportioning of fuel supply to throttle-opening alonetends to cause stalling when the load increases Without change inthrottle-opening.

A carburetor according to the present invention, besides assuring anadjustably constant fuel supply for idling, proportions fuel supply tothrottle-opening in the lower ranges of throttle-opening, and to enginesuction in the higher ranges of throttle-opening. In addition, by meansof pressure drop in a continuouslyfiowing stream of fuel adjacentthepoint of delivery to the venturi, the carburetor according to thisinvention balances a counter-suction within the feed-line againstengine-suction in the higher ranges of throttle-opening, therebypreventing over-supply of fuel at full throttle operation.

In order to disclose the invention, a carburetor is here shown whichembodies the preferred features of design, and is here shown forpurposes of illustrationonly.

Referring to the drawings annexed to and forming part ZGof-.

v Fig. 1 is a vertical longitudinal section through "the carburetorinthe plane" 1, 1 of Fig; 2. V a

Fig. 2'is in part aplan, and in part a horizontal section in the plane2, 2 of Fig. l, of said carburetor.

Fig. 3 is an end elevation of the same.

Fig. 4 is a partial diagrammatic horizontal section in the plane 4, 4 ofFig; 1 illustrating in solid lines the idling position, and in dottedlines the half open and fully open positions of can-is 23, 24, rollers48, 69 arid throttle 14.

Fig. 5 is a partial horizontal section in the planes 5, 5 of Fig. l,showingthe eccentric mounting of roller 48.

Fig. 6 is a vertical elevation, with some parts in section, of theelements appearing in Fig. 5.

Referring to these drawings I I A central casting 10 contains acylindrical bore 11 containing a Venturisleeve 12, a fuel bridge 13 anda throttle valve 14 secured upon shaft 15. Air entersat the top of bore11, moves downwardly through Venturi sleeve 12 where fuel is injectedand vaporized, and the resulting explosive mixtuie then passesdownwardly to the cylinders of the engine (notshown); v a Scuredjtoopposite Sidesjof casting 10 arecasing member 16 andl17' shapedtofo'rrn' chambers18 and 19, re-

" 'hsid j o jc t a ,ca t g'10, e h of a portion pf the valve operatingmech- I. esc i d.

the wall of casting v a m, 14; pro e sin'each direczti'oiith'roughthe-lower portien's or chambers 18 and 19,

ice

' penetrates the exterior walls thereof in bearings 20, 20a,

and has screw-threaded ends 21 and 22 exposed at each end of thecarburetor; Secured upon shaft 15, to rotate therewith, are a pair ofoppositely facing arcuate cams 23, 24 which serve to actuate the fuelvalves in response to throttle opening as hereinafter described.

Casing 16 encloses and protects the actuating mechanism for fuel inletvalve .25 adapted toregister with seat 2'6formed at one end of apassageway 27 extending across bridge 13. Passageway 27 comprises aportion28 of restricted diameter and arportion 29 of larger diameter,these two portions meeting at point 30, A lateral fuel passageway 31communicating with the portion 29 of larger diameter immediatelyadjacent point is adapted to conduct fuel from portion 29 to a series ofdischarge openings 32 where liquid fuel maybe discharged into thevaporizing chamber 33 defined by Venturi sleeve 12. A head 34 serves toprotect discharge openings 32 from air pressure which might tend toresist the discharge of fuel into chamber 33.

Casing 17 encloses and protects the actuating mechanism for fuel outletvalve 35 adapted to engage with seat 36 Which defines the end of portion29 of larger diameter of the fuel passageway 27. a a

Liquid fuel, for example gasoline, is fed to the carburetor throughpassageway 37 and thence to fuel chamber 33 defined by drillings in thewall of casting 10 .and by diaphragm 39 at the center of which inletvalve 25 is mounted. Diaphragm 39 is suitably secured around itsmarginal edges to prevent escape of liquid fuel from chamber 33. Excessfuel passing between valve 25 and its seat 26, through passageway 27,and then betweenoutlet valve 35 and its seat 36, enters chamber 40defined by drillings inthe wall of casting 10' and by diaphragm 41 atthe center of which valve 35 is mounted. Diaphragm 41 is suitablysecured around its marginal edges to prevent escape of fluid fromchamber 40, I

From chamber 4 ll exc'e'ss fuel passes to passageway, 42 and thence isreturned to the source. An' engine driven fuel pump (not shown)continually provides a supply of liquid fuel under pressure throughpassageway 37 to chamber 38, while the engine is operating, andexcessfuel not used in the carburetor but passing across bridge 13 intochamber 40, is continually returned to the source through passageway 42.I Thus, When both of valves 25 and 35 are open, the carburetor operatesunder constant recirculation of fuel supply. I V v 7 Valve 25 ismounted, as hereinafter described, in such manner that its opening isresponsive to the opening of throttle valve 14. More particularly, thearrangement is such that when throttle 14 begins to open, valve 25 movesaway from seat 26 and the response' is mechanically direct throughoutthe opening of valve 14. However, valve 25 never completely closes. Inthe position in which this valve is shown in Fig. 1, the minimum valveopening permits sufiicient fuel to pass the valve for engine idlingpurposes. Valve 25 is supported at the upper endof movable arm 43projecting upwardly from and integral with a frame 44 slideable upon apair of lateral guide rods 45, 46 (Fig. 2) and a fixed guide rod 47. Atits end nearest to casting 10, frame 44 supports an eccentricallymounted roller 48, the details of which are shown in Figs. 5 and 6.

Referring more particularly to Figs. 5 and 6; frame 44, at the placewhere roller 48 is mounted, consists of an upper plate 49 and a lowerplate 50. A headed disc 51 is rotatably mounted within a bore 52 inupper plate 49.. A stub shaft 53 is rotatably mounted within a. bore'54in lower plate which said bore is coaxialwith bore, 52. Roller shaft 55,of smaller diameter than disc 51 and shaft 53, is firmly drivenintobores 56 and 57in the ends armor so as to make a tight non-rotatableconnection therewith. Shaft is thus partnered eccefitriany with arsaossrespect to disc 51 and shaft 53 which are coaxial with each other.Roller 48 is mounted upon shaft 55 and is free to rotate thereon, beingsecured against endwise displacement by the contact of its endsrespectively with disc 51 and shaft 53. Lever 58 secured upon the lowerend of stub shaft 53 has fastened to its outer end a Bowden wire 59 bymeans of which lever 58 can be rocked manually or automatically from theposition shown in solid lines in Fig. to the position 58a shown indotted lines. Thus the center of rotation 76 of roller 48 may be swungthrough an are about the center of rotation 77 of shaft 53, for apurpose to be explained. A spring 78 secured to frame 44 tends to pullarm 58 against the tension of Bowden wire 59 against a stop pin 79.

Spring 60 (see Fig. 1), preferably coiled about guide rod 47 and havingits ends interposed between the interior of casing 16 and an exposedsurface of frame 44, is adapted to urge frame 44 yieldingly in adirection such as to press roller 48 into engagement with cam 23. Thus,movement of cam 23 so as to transmit pressure against roller 48 tends tomove frame 44, and hence to move valve 25 away from its seat 26. Theeccentric mounting of roller 48 permits relative adjustment between theposition of throttle valve 14 and of fuel valve 25, in their respectivetraverses. Thus, idling adjustment may be made by means of Bowden wire59.

Fuel outlet valve 35 is secured at the upper end of movable arm 61 whichin turn is secured to and integral with movable frame 62. Frame 62carries a pair of guide rods 63, 64 which respectively engage within apair of parallel bores 65, 66 in the lower portion of casting 10. Fixedguide rod 67 secured in casing 17 slideably engages within a socket 68in frame 62, thereby further helping to guide frame 62 in its linearpath of travel. At its end nearest to casting 10, frame 62 carries aroller 69 freely rotatable upon a shaft 70 fixed in frame 62. A helicalspring 71 interposed between casing 17 and a surface of frame 62yieldingly urges roller 69 into engagement with cam 24. The arrangementis such that movement of cam 24 tending to transmit pressure againstroller 69 moves frame 62 and movable arm 61 in a direction away fromcasting 10, and hence moves fuel outlet valve 35 away from its seat 36.

Cams 23 and 24 are shaped (see Fig. 4) to have low portions 81 and 82,and sloping portions 83 and 84, respectively, but of differing lengthsas will be explained. When throttle valve 14 is in closed (idle)position as shown in Fig. 4, roller 48 and 69 rest in contact with lowportions 81 and 82 respectively of the cams. When throttle valve 14'hasbeen moved partway towards open position, for example, to theintermediate position shown in dotted lines 80, and both cams have beenmoved to the respective positions indicated at 23a and 24a, the slopingportion 83 of cam 23 engages roller 48 and displaces it laterally, forexample, to the position shown in dotted lines 48a. Since the lowportion 82 of cam 24 is longer than the low portion 81 of cam 23, thismovement of the cams is insufficient to bring sloping portion 84 of cam24 into engagement with roller 69. Accordingly, at this stage, roller 69remains undisplaced while roller 48 is displaced to position 48a. When,however, throttle valve 14 has been moved still further towards openposition, for example, to the position shown in dotted lines 74, andboth cams have been moved to the respective positions indicated at 23band 24b, the sloping portion 83 of cam 23 displaces roller 48 to theposition indicated in dotted lines at 48b, and the sloping portion 84 ofcam 24 engages roller 69 and displaces it laterally to the positionindicated in dotted lines 691).

Thus, movement of the cams, which is mechanically or 69 causes equaldisplacement, i. e., opening, of the corresponding valve 25, 35.

Operation-When the engine is not running, fuel in let valve 25 and fueloutlet valve 35 are normally in the positions shown in Fig. 1. That is,fuel inlet valve 25 is slightly open and fuel outlet valve 35 is closed.At this time throttle valve 14 is very nearly or almost at its closedposition, the low points of earns 23 and 24 are respectively in contactwith the peripheries of rollers 48 and 69, and frames 44 and 62 arespring pressed to their extreme inward positions nearest to centralcasting 10, all as shown in Fig. 1.

When the engine has been started and brought to idling speed, the partsof the carburetor will normally remain substantially in the positionsalready described. The running of the engine causes a pump (not shown)to deliver asoline through passageway 37 to chamber 38 and thence pastslightly open valve 25 to passageway 27 including portion 29 thereof oflarger diameter. Since, at this position of the parts, valve 35 remainstightly closed, all fuel which passes valve 25, except the amountrequired to fill passageway 27, is discharged under pump pressurethrough passageway 31 and discharge openings 32 into the vaporizingchamber 33, defined by Venturi sleeve 12. in order to adjust the amountof fuel which will be delivered through valve 25 under thme conditions,the axial position of roller 48 in relation to frame 44 may be adjustedby means of a Bowden wire 59 which rocks lever 58. As the engine warmsup lever 58 is moved towards position 58a (Fig. 5) either manually or bya thermostat (not shown).

When the throttle is to be opened in order to supply more fuel to theengine, shaft may be rocked by any suitable means in a counterclockwisedirection as seen in Fig. 3. This may be done, for example, by means ofa lever engaged upon either end 21 or 22 of shaft 15. Rotation of shaft15 causes throttle valve 14 to move from its almost closed positionshown in Figs. 1, 2 and 4, towards open position. It also causes earns23 and 24,which are secured to shaft 15, to rotate about theirrespective centers and thus to move the low portions of these cams pastrollers 48 and 69 respectively. As the cams move together (downwardly asseen in diagrammatic Fig. 4) roller 48 begins to ride the incline 83 ofearn 23 while roller 69 remains on low portion 82 of cam 24. Thus,during the initial stages of the opening of throttle valve 14, fuelinlet valve is being progressively opened while fuel outlet valve 35remains closed. Thus, during this phase of the operation, increase offuel supply through openings 32 is governed by increased opening ofvalve 25.

When the engine is being operated under conditions of a still largerthrottle opening, as for example, that indicated. in dotted lines 74,each of rollers 48 and 69 will be in contact with inclined portions 83and 84 of cams 23 and 24, respectively. As the throttle approaches fullopening. the rollers climb to the tops of these inclines respectively.Thus, roller 69 is moved outwardly and with it frame 62, arm 61 and fueloutlet valve 35 all of which are connected to roller 69. Movement ofvalve 35 away from its seat 36 permits liquid fuel to flow continuouslythrough passageway 27. Thus, during the phase of operation. when valve35 is open, the supply of fuel in passageway 27 constitutes acontinuously circulating supply maintained by the pump and fed from asource of supply (not shown) through passageway 37 and chamber 38,thence through passage 27 to chamber 40, and returning to the source ofsupply through passageway 42. Under these conditions fuel is flowingcontinuously at high velocity through portion 28 of restricted diameterinto portion 29 of larger diameter, and thereby experiences asubstantial change in pressure and in velocity at the point where thechange in diameter occurs. Lateral fuel passageway 31 is so located asto communicate with larger diametered portion 29 of the passagewayimmediately adjacent point 30. Thus, when valve is open and acontinuously states flowing stream of fuel is passing through passage 27across bridge 13', the feed of liquid fuel through openings 32 tovaporizingchamber 33 is nolonger dependent on direct fuel pump pressure(governed by the degree of opening of valve but is now dependent on thedifference in pressure existing in vaporizing'chamber 33 and at point 39in the flowing stream of fuel. For all greater degrees of throttleopening, beyond'that required to initiatethe opening of valve 35, feedof liquid fuel to the Venturi is govcreases, the pressure at isdiminished. Consequently the carburetor is automatically correlated tothe relative pressures of the flowing liquid fuel and the pressure inthe vaporizing chamber at high speed, and thus permitsa more eflicientuse of the fuel.

By the means aforesaid, there is provided a floatless carburetor inwhich the feed of fuel at lesser degrees of throttle opening (whilevalve 35 is closed) is positively provided by the force of the fuel pumpunder control of valve 25 which may be adjusted by means of Bowden wire59. However, at lafger degrees of throttle opening, when valve ,35 isopened the feed of fuel to the vaporizing chamber is dependent upon thesuction in the vaporizing chamber defined by Venturi l2 and fuel isdrawn from a continuously circulating supply thereof which is passingacross bridge 13 through passageway 27 in the interior thereof. Duringthe latter phase of-operation, fuel is being pumped into the carburetorthrough passageway 37, excess fuel is being returned-from the'carburetorto the source of sup ply through passageway 42, and the amount of fueldrawn is dependent'upon the relative pressures in passageway 27 and'invaporizing chamber 33. Additionally, there is provid'ed, according tothis invention means to modify the pressure of the flowing fuel inpassageway 27, consisting of a transition point 36 between where fuelissues from a portion 23 of passageway which is of smaller diameter intoa portion 29 of largerdiameter. At this point a substantial change inpressure occurs. When the velocity of flow of fuel'through passageway 27increases, the pressure inthe' fluid as it passes point 30 changesinversely to the changes in velocity.- Hence, a relation is preservedbetween the pressureand velocity'of the fuel inside bridge 13'and'theair inside the Venturi'12, resulting in economy in. the'use of fuel.

Since a carburetor made according to this invention is not dependentupon gravity for the feeding of fuel, or for the maintenance of desiredpressure, the carburetor is adapted to be installed in any desired axialrelation to the vertical, and if installed vertically will perform withequal facility when the engine to which it is attached has been tippedor tilted in any-manner.

What'is'claimed is:

l. Ina device-of the character described comprising a flo'atle'ssrecirculating, carburetor having a vaporizing chamber and throttle forcontrolling the flow of vaporized combustible mixture and means,forfeedingxfuel to the carburetor, in combination, a fuel conduit, anozzle for discharge offuel' from saidconduit'int'o an air streamflowing inssaid-vaporizing chamber, a'n'inlet valve adapted to controlthe flow ofliquidfuel tothe conduit, an outlet valve controlling. theflow ofexcessful from the conduit, and means responsive to partialopening movement of the throttle to open the inlet valve while holdingthe out let valve closed, and on further opening movement of thethrottle to open both said valves, whereby the feed of fuel ispositively provided by the pressure of the fuel supply at lesser degreesof throttle opening and by the relative pressures of the flowing liquidfuel and the vaporizing chamber at greater degrees of throttle opening.

2. In a device of the character described comprising a floatlessrecirculating carburetor having a vaporizing chamber and throttle forcontrolling hssbyvprvspenzsd combustible mixture and means for feldm'gfuel to the carburetor, in combination, a fuel conduit, a nozzle fordischarge of fuel from said conduit intoan air stream flowing in saidvaporizing chamber, an inlet valve member adapted to control theflow ofliquid, fuel to the conduit, means movable with the throttle valve tomove said inlet valve member towards and away from closed position whenthe throttle valve is moved, an outlet valve member adapted to movetowards and away from closed position for controlling the flow of excessfuel from the conduit, and means interconnected with the throttle tohold said outletvalve member in closed position when the throttle ispartly open and to move said outlet valve member from closed to openposition when the throttle is fully opened, whereby the feed of fuel ispositively provided by the pressure of the fuel supply at lesser degreesof throttle opening and by the relative pressures of the flowing liquidfuel and the vaporizing chamber at greater degrees of throttle opening.s

3. In a device of the character described comprising a fi oatlessrecirculating carburetor having a vaporizing chamber and throttle forcontrolling the fiow of vaporized combustible mixture and means for.feeding fuel to the carburetor, in combination, a fuel conduit, a nozzlefor discharge of fuel from said conduit into an air stream flowing insaid vaporizing chamber, an inlet valve member adapted to control theflow of liquid fuel to the conduit, means movable with the throttle tomove said inlet valve member towards and awayfrom'closed' position whenthe throttle is moved, an outlet valve member controlling the flow ofexcess fuel from the conduit,-a rotatably-mounted control shaft by whichsaid throttle is moved, and cam means secured to said shaft and adaptedto hold said outlet valve closed when the throttle is partly open and tomove the outlet valve to open position when the throttle is fullyopened, whereby the feed of fuel is positively provided by the pressureof the fuel supply at lesser degrees of throttle opening and by therelative pressures of the flowing liquid fuel and the vaporizing chamberat greater degrees of throttle opening. v

4. in a device of the character described comprising afloatlessrecirculating carburetor having a vaporizing chamber and throttle forcontrolling the flow of vaporized combustible mixture and means forfeeding fuel to the carburetor, in combination, a membervhaving a fuelpassageway, a nozzle for discharge of fuel from said passageway into anair stream flowing in said vaporizing chamber, an inlet valve adapted tocontrol the flow of liquid fuel to the fuel passageway, means including.an outlet valve for controlling the flow of excess fuel from said fuelpassageway to said fuel feeding means, and

means interconnected with the/throttle to hold said outlet valve closedwhen the throttle is partly open and to move said outlet valve to openposition when the throttle is fully opened, whereby the feed of fuel ispositively provided by the pressure of the fuel supply at lesser degreesof throttle opening and by the relative pressures of the flowing liquidfuel and the vaporizing chamber at greater degrees of 'thro'ttleopening.

5. In a device of the character described comprisingla floatlessrecirculatingcarburetor having a vaporizing chamber and throttle forcontrolling, theflow of vaporized combustible mixture and mean s forfeeding fuelto'the carburetor, in combination, a member having a fuelpas sageway of predetermined relatively small cross-sectional area and asecond fuel passageway of predetermined relatively largercross-sectional area communicating with said first-mentioned passagewayand adapted to receive fuel therefrom through an orifice, a nozzle fordischarge of fuel from said second fuel passageway into an air streamflowing in said vaporizing chamber, an inlet valve adapted to controlthe flow of liquid fuel to said first named passageway, means includingan outlet valve controlling the flow of excess fuel from the passagewayof relatively .larger cross-sectional area to said fuel feeding means,and

V the outlet valve to open position when the throttle is fully opened,whereby the feed of fuel is positively provided by the pressure of thefuel supply at lesser degrees of throttle opening and by the relativepressures of the flowing liquid fuel and the vaporizing chamber atgreater degrees of throttle opening.

6. In a device of the character described comprising a floatlessrecirculating carburetor having a vaporizing chamber and throttle forcontrolling the .fiow of vaporized combustible mixture and means forfeeding fuel to the carburetor, in combination, a member having a fuelpassageway of predetermined relatively small cross-sectional area and asecond fuel passageway of predetermined relatively largercross-sectional area communicating with said first-mentioned passagewayand adapted to receive fuel therefrom through an orifice, a nozzle fordischarge of fuel from said second fuel passageway into an air streamflowing in said vaporizing chamber, an inlet valve adapted to controlthe flow of liquid fuel to said first-named passageway, means movablewith the throttle to move said inlet valve towards and away from closedposition when the throttle is moved, an outlet valve controlling theflow of excess fuel from the passageway of relatively largercross-sectional area, and means interconnected with the throttle to holdsaid outlet valve closed when the throttle is partly open and to movethe outlet valve to open position when the throttle is fully opened,whereby the feed of fuel is positively provided by the pressure of thefuel supply at lesser degrees of throttle opening and by the relativepressures of the flowing liquid fuel and the vaporizing chamber atgreater degrees of throttle opening.

7. In a device of the character described comprising a floatlessrecirculating carburetor having a vaporizing chamber and throttle forcontrolling the flow of vaporized combustible mixture and means forfeeding fuel to the carburetor, in combination, a member having a fuelpassageway,.a nozzle for discharge of fuel from said passageway into anair stream flowing in said vaporizing chamber, an inlet valve adapted tocontrol the flow of liquid fuel to the fuel passageway, a pressuremodifying orifice in said passageway, a fuel discharge openingcommunicating with said passageway on the side of the orifice remotefrom said inlet valve, means movable with the throttle to move saidinlet valve towards and away from closed position when the throttle ismoved, an outlet valve controlling the flow of excess fuel from thepassageway, and means interconnected with the throttle to hold saidoutlet valve closed when the throttle is partly open and to move theoutlet valve to open position when the throttle is fully opened. wherebythe feed of fuel is positively provided by the pressure of the fuelsupply at lesser degrees of throttle opening and by the relativepressures of the flowing liquid fuel and the vaporizing chamber atgreater degrees of throttle opening.

8. In a device of the character described comprising a floatlessrecirculating carburetor having a vaporizing chamber and throttle forcontrolling the flow of vaporized combustible mixture and means forfeeding fuel to the carburetor, in combination, a fuel conduit, a nozzlefor dis charge of fuel from said conduit into an air stream flowing insaid vaporizing chamber, an inlet valve member adapted to control theflow of liquid fuel to the conduit, a

movable carriage supporting said member, an outlet valve member adaptedto control the flow of excess fuel from the conduit, 9. second movablecarriage supporting said last-named member, a rotatably-mounted controlshaft by which said throttle is moved, and a pair of cams secured tomove with said shaft and adapted to bear against said carriagesrespectively, whereby movement of the throttle under control of saidshaft is.accompanied by movement of said inlet and outlet fuel valves toopen the inlet valve while holding the outlet valve closed and onfurther opening of the throttle to open both of said valves, whereby thefeed of fuel is positively provided by the pressure of the fuel supplyat lesser degrees of throttle opening and by the relative pressures ofthe flowing liquid fuel and the vaporizing chamber at greater degrees ofthrottle opening.

9. in a device of the character described comprising a floatlcssrecirculating carburetor having a vaporizing chamber and throttle forcontrolling the flow of vaporized combustible mixture and means forfeeding fuel to the carburetor, in combination, a fuel conduit, a nozzlefor discharge of fuel from said conduit into an air stream flowing insaid vaporizing chamber, an inlet valve member adapted to control theflow of liquid fuel to the conduit, a

movable carriage adapted to support said valve member and to move thesame towards and away from closed position, a roller eccentricallymounted upon a rock-shaft supported by said carriage, means to rock saidrock-shaft. cam means interconnected with the throttle and adapted toengage said roller whereby to cause said carriage to move when thethrottle is moved, an outlet valve controlling the flow of excess fuelfrom the conduit, and means interconnected with the throttle to holdsaid outlet valve closed when the throttle is partly open and to movethe outlet valve to open position when the throttle is fully opened,whereby the feed of fuel is positively provided by the pressure of thefuel supply at lesser degrees of throttle opening and by the relativepressures of the flowing liquid fuel and the vaporizing chamber atgreater degrees of throttle opening.

10. In a device of the character described comprising a floatlessrecirculating carburetor having a vaporizing chamber and throttle forcontrolling the flow of vaporized combustible mixture and means forfeeding fuel to the carbureton in combination, a fuel conduit, a nozzlefor discharge of fuel from said conduit into an air stream flowing insaid vaporizing chamber, an inlet valve member adapted to control theflow of liquid fuel to the conduit,

a movable carriage supporting said inlet valve member,

and having a roller whose center of rotation may be moved for purposesof adjusting the valve opening means for moving the center of rotationof said rollers, an outlet valve controlling the flow of excess fuelfrom the conduit, a second movable carriage supporting said outlet valvemember and having a second roller, and a shaft supporting the throttleand also supporting cam means engageable with said rollers when theshaft is rotated whereby the feed of fuel is positively provided by thepressure of the fuel supply at lesser degrees of throttle opening and bythe relative pressures of the flowing liquid fuel and the vaporizingchamber at greater degrees of throttle opening.

References Cited in the file of this patent UNITED STATES PATENTS1,164,093 Houghton et al. Dec. 14, 1915 2,136,959 Winfield Nov. 15, 19382,595,720 Snyder May 6, 1952

